Nerve impulse - Action potential
A nerve impulse is an electrical charge that travels along the length of a neuron. An impulse is the result of a stimulus, such as contact with a surface or perhaps a loud noise that makes you jump.
Another name for a nerve impulse is an action potential. The minimum stimulus capable of generating an action potential is called the threshold. However, a stronger stimulus does not generate a larger action potential. Action potentials obey the all-or-nothing principle. This means that a nerve impulse can only be strong enough to travel through the neuron, or it cannot be strong enough.
References:
Biology, Glencoe/McGraw-Hill
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